The operation and interoperation of local area networks (LAN) and metropolitan area networks (MAN) are governed by a number of standards developed through IEEE 802, IETF and ITU Working Groups.
For example, the 802.3 Working Group develops standards related to Local Area Networks (LAN), such as Ethernet networks.
Fiber optics are gaining wider acceptance as the media of choice for interconnecting LANs with high capacity or serving as the backbone for MANs. The need for higher bandwidth and improvements in optical switching have been large factors in the increasing demand for optical networks.
A typical Ethernet over optical fiber network relies upon a SONET/SDH layer in the Metropolitan Area Network and Campus environment to provide for resiliency to hardware failures at the physical layer. The SONET/SDH layer necessarily adds certain operational complexity to the communications.
Multiple Ethernet signals can be multiplexed on a single optical fiber using wavelength division multiplexing technology (WDM). When using WDM the signals are all assigned a unique wavelength and are allowed to share a single optical fiber. When using WDM technology Ethernet signals are normally encapsulated in a SONET or OTN frame. The SONET/SDH layer necessarily adds certain operational complexity to the communications.
Cost saving in terms of equipment and bandwidth may be realized by eliminating the SONET/SDH layer; however, the Ethernet layer would become vulnerable to failures at the physical layer.
The IEEE 802.3 Working Group has defined a link aggregation standard, known as IEEE 802.3ad. However, this standard is predicated on a physical layer that supports a resilient transport network such as a SONET/SDH layer. The 802.3ad standard thus makes no provision for the failure and resiliency attributes of a directly-connected WDM network (i.e. a WDM optical network without an optical control layer).
Accordingly, it would be advantageous to have a method for configuring a connection-oriented packet network, like an Ethernet network, over a WDM optical network without an optical control layer.
Moreover, the IETF MPLS Working Group develops standards related to networks that operate on the basis of label switch paths (LSP) that tunnel lower layer services across an internet protocol (IP) network. The IETF PWE3 Working Group develops standards for link concatenation structures, known as pseudo-wires, that may be constructed on a variety of network types including MPLS, IP, Ethernet and SONET networks. By way of the methods prescribed in the IETF standards, complex layered networks may be configured. For example, a point-to-point Ethernet service may be configured using pseudo-wires that exploit MPLS label switch routes that are themselves configured over an underlying IP/Ethernet/transport network.
A typical MPLS network achieves resiliency by way of a underlying routing IP layer, or an underlying Ethernet link aggregation layer, that themselves achieve resiliency by way of an underlying SONET/SDH layer. The SONET/SDH layer necessarily adds certain operational complexity to the communications and thereby reduces effective bandwidth. As indicated above, cost saving in terms of equipment and bandwidth may be realized by eliminating the SONET/SDH layer at the expense of resiliency.
The IETF MPLS and pseudo-wire Working Groups have provided standard methods for concatenating links to define routes through a network. Further, drafts submitted at IETF Working Groups have included proposals for an Optimized Multipath Algorithm that combines MPLS label switch paths according to an algorithm, so as to create a structure similar to that of an IEEE 802.3ad link aggregation structure but where the links are LSPs instead of Ethernet links.
Accordingly, it would be advantageous to have a method for configuring a connection-oriented packet network, like an MPLS network or a pseudowire network, over a WDM optical network without an optical control layer.
More broadly, it would be advantageous to provide for a network planning tool and method that improves Ethernet, MPLS, pseudo-wire and/or Optimized Multipath Algorithm resiliency in the absence of an underlying resilient layer.